The present invention relates to a blister package for an optical lens, especially a soft hydrophilic contact lens, according to the preamble of claim 1.
Soft hydrophilic contact lenses are generally manufactured from hydrophilic polymer material, e.g. copolymers of hydroxyethyl methacrylate (HEMA) and, depending on the polymer composition, may have a water content of 20% to 90% and more. Contact lenses of this kind have to be kept and stored in a sterile solution, normally an isotonic sodium chloride solution, in order to avoid drying out and to keep the lenses ready for use.
A blister package of the generic type designed for this type of soft hydrophilic contact lenses is described in EP 0 680 895 A1. The cavity of this package which accepts the contact lens is not explicitly adapted to the shape of the contact lens. To simplify removal of the contact lens, the cavity has a cap-shaped primary area and a secondary area attached to the side of this, which has the shape of a channel that tapers on all sides away from the primary area, whereby the primary area merges flush with the secondary area, and the primary area and secondary area together have a drop-shaped contour. The base part of the blister package is produced e.g. from polypropylene, usually in an injection moulding or forming process. The base parts are prepared individually and supplied in bulk. In the case of bulk-produced material, the cups are deformed by storing and transporting, with the result that the further packaging procedure may be disrupted. In addition, the work and therefore costs of sorting and supplying the individual cups are very high.
The invention is concerned with the problem of improving the known blister package in such a way that the base parts can be stacked and the work involved in sorting can be substantially reduced.
The blister package according to the invention, which solves this problem, is defined in the independent claim 1. Further structures and developments may be seen in the dependent claims.
By providing the base parts with spacing elements, it is possible to have smooth stacking thereof. Moreover, by connecting several base parts to one packaging unit, it is possible to improve handling of the base parts in the production process.